sound source of frequency f moves with constant velocity (less than the speed of sound) through a medium that is at rest. A stationary observer hears a sound whose frequency is appreciably different from f because

A static observer hears a sound whose frequency is appreciably different from actual frequency because here the change in frequency of the sound due to doppler effect.

Explanation:

Given that,

Frequency = f

We know that,

The sound source of frequency f moves with constant velocity through a medium that is at rest.

A static observer hears a sound whose frequency is significantly different from actual frequency due to doppler effect.

We know that,

The doppler effect is defined as

Where, f₀ = actual frequency

f = observe frequency

v = speed of sound

= speed of observer

= speed of source

Hence, A static observer hears a sound whose frequency is significantly different from actual frequency because here the change in frequency of the sound due to doppler effect.

i don't know that i agree with that but what's the question ?